diff --git a/src/Chromosome.php b/src/Chromosome.php
new file mode 100644
index 0000000..784b271
--- /dev/null
+++ b/src/Chromosome.php
@@ -0,0 +1,37 @@
+<?php declare(strict_types=1);
+
+namespace MLL\Utils;
+
+class Chromosome
+{
+    private string $value;
+
+    private NamingConvention $namingConvention;
+
+    public function __construct(string $chromosomeAsString)
+    {
+        /** Matches human chromosomes with or without "chr" prefix: chr1-chr22, chrX, chrY, chrM, chrMT, or 1-22, X, Y, M, MT. */
+        if (\Safe\preg_match('/^(chr)?(1[0-9]|[1-9]|2[0-2]|X|Y|M|MT)$/i', $chromosomeAsString, $matches) === 0) {
+            throw new \InvalidArgumentException("Invalid chromosome: {$chromosomeAsString}. Expected format: chr1-chr22, chrX, chrY, chrM, or without chr prefix.");
+        }
+        $this->namingConvention = $matches[1] === 'chr'
+            ? new NamingConvention(NamingConvention::UCSC)
+            : new NamingConvention(NamingConvention::ENSEMBL);
+
+        $this->value = strtoupper($matches[2]);
+    }
+
+    public function toString(?NamingConvention $namingConvention = null): string
+    {
+        $namingConvention ??= $this->namingConvention;
+
+        switch ($namingConvention->value) {
+            case NamingConvention::ENSEMBL:
+                return $this->value === 'M' ? 'MT' : $this->value;
+            case NamingConvention::UCSC:
+                return "chr{$this->value}";
+            default:
+                throw new \InvalidArgumentException("No toString logic implemented for valid naming convention: {$namingConvention->value}");
+        }
+    }
+}
diff --git a/src/GenomicPosition.php b/src/GenomicPosition.php
new file mode 100644
index 0000000..f354d9e
--- /dev/null
+++ b/src/GenomicPosition.php
@@ -0,0 +1,35 @@
+<?php declare(strict_types=1);
+
+namespace MLL\Utils;
+
+class GenomicPosition
+{
+    public Chromosome $chromosome;
+
+    public int $position;
+
+    public function __construct(Chromosome $chromosome, int $position)
+    {
+        if ($position < 1) {
+            throw new \InvalidArgumentException("Position must be positive, got: {$position}.");
+        }
+
+        $this->chromosome = $chromosome;
+        $this->position = $position;
+    }
+
+    /** @example GenomicPosition::parse('chr1:123456') */
+    public static function parse(string $genomicPosition): self
+    {
+        if (\Safe\preg_match('/^(.+):(g\.|)(\d+)$/', $genomicPosition, $matches) === 0) {
+            throw new \InvalidArgumentException("Invalid genomic position format: {$genomicPosition}. Expected format: chr1:123456.");
+        }
+
+        return new self(new Chromosome($matches[1]), (int) $matches[3]);
+    }
+
+    public function toString(?NamingConvention $namingConvention = null): string
+    {
+        return "{$this->chromosome->toString($namingConvention)}:{$this->position}";
+    }
+}
diff --git a/src/GenomicRegion.php b/src/GenomicRegion.php
new file mode 100644
index 0000000..0195bcd
--- /dev/null
+++ b/src/GenomicRegion.php
@@ -0,0 +1,89 @@
+<?php declare(strict_types=1);
+
+namespace MLL\Utils;
+
+use function Safe\preg_match;
+
+final class GenomicRegion
+{
+    public Chromosome $chromosome;
+
+    public int $start;
+
+    public int $end;
+
+    public function __construct(
+        Chromosome $chromosome,
+        int $start,
+        int $end
+    ) {
+        if ($start < 1) {
+            throw new \InvalidArgumentException("Start must be positive, got: {$start}.");
+        }
+
+        if ($end < 1) {
+            throw new \InvalidArgumentException("End must be positive, got: {$end}.");
+        }
+
+        if ($start > $end) {
+            throw new \InvalidArgumentException("End ({$end}) must be greater than start ({$start})");
+        }
+
+        $this->chromosome = $chromosome;
+        $this->start = $start;
+        $this->end = $end;
+    }
+
+    public static function parse(string $genomicRegion): self
+    {
+        if (preg_match('/^(.+):(g\.|)(\d+)(-(\d+)|)$/', $genomicRegion, $matches) === 0) {
+            throw new \InvalidArgumentException("Invalid genomic region format: {$genomicRegion}. Expected format: chr1:123-456.");
+        }
+
+        return new self(
+            new Chromosome($matches[1]),
+            (int) $matches[3],
+            (int) ($matches[5] ?? $matches[3])
+        );
+    }
+
+    public function containsGenomicPosition(GenomicPosition $genomicPosition): bool
+    {
+        return $this->chromosome->toString() === $genomicPosition->chromosome->toString()
+            && $this->positionIsBetweenStartAndEnd($genomicPosition->position);
+    }
+
+    public function containsGenomicRegion(GenomicRegion $genomicRegion): bool
+    {
+        return $this->chromosome->toString() === $genomicRegion->chromosome->toString()
+            && $this->positionIsBetweenStartAndEnd($genomicRegion->start)
+            && $this->positionIsBetweenStartAndEnd($genomicRegion->end);
+    }
+
+    public function isCoveredByGenomicRegion(GenomicRegion $genomicRegion): bool
+    {
+        return $this->chromosome->toString() === $genomicRegion->chromosome->toString()
+            && $genomicRegion->start <= $this->start
+            && $genomicRegion->end >= $this->end;
+    }
+
+    public function intersectsWithGenomicRegion(GenomicRegion $genomicRegion): bool
+    {
+        return $this->chromosome->toString() === $genomicRegion->chromosome->toString()
+            && (
+                $this->isCoveredByGenomicRegion($genomicRegion)
+                || $this->positionIsBetweenStartAndEnd($genomicRegion->start)
+                || $this->positionIsBetweenStartAndEnd($genomicRegion->end)
+            );
+    }
+
+    private function positionIsBetweenStartAndEnd(int $position): bool
+    {
+        return $position >= $this->start && $position <= $this->end;
+    }
+
+    public function toString(?NamingConvention $namingConvention = null): string
+    {
+        return "{$this->chromosome->toString($namingConvention)}:{$this->start}-{$this->end}";
+    }
+}
diff --git a/src/NamingConvention.php b/src/NamingConvention.php
new file mode 100644
index 0000000..be0d5cb
--- /dev/null
+++ b/src/NamingConvention.php
@@ -0,0 +1,23 @@
+<?php declare(strict_types=1);
+
+namespace MLL\Utils;
+
+class NamingConvention
+{
+    public const ENSEMBL = 'ENSEMBL';
+    public const UCSC = 'UCSC';
+
+    public string $value;
+
+    public function __construct(string $value)
+    {
+        switch ($value) {
+            case NamingConvention::ENSEMBL:
+            case NamingConvention::UCSC:
+                $this->value = $value;
+                break;
+            default:
+                throw new \InvalidArgumentException("Invalid naming convention: {$value}");
+        }
+    }
+}
diff --git a/tests/ChromosomeTest.php b/tests/ChromosomeTest.php
new file mode 100644
index 0000000..da9ac22
--- /dev/null
+++ b/tests/ChromosomeTest.php
@@ -0,0 +1,40 @@
+<?php declare(strict_types=1);
+
+use MLL\Utils\Chromosome;
+use MLL\Utils\NamingConvention;
+use PHPUnit\Framework\TestCase;
+
+final class ChromosomeTest extends TestCase
+{
+    public function testToStringWithDefault(): void
+    {
+        $chromosome = new Chromosome('chr11');
+        self::assertSame('chr11', $chromosome->toString());
+    }
+
+    public function testToStringForEnsembl(): void
+    {
+        $chromosome = new Chromosome('chr11');
+        self::assertSame('11', $chromosome->toString(new NamingConvention(NamingConvention::ENSEMBL)));
+    }
+
+    public function testInitWithUCSC(): void
+    {
+        $chromosome = new Chromosome('11');
+        self::assertSame('11', $chromosome->toString());
+    }
+
+    public function testToStringWithUCSCAndMitochondrialChromosome(): void
+    {
+        $chromosome = new Chromosome('chrM');
+        self::assertSame('MT', $chromosome->toString(new NamingConvention(NamingConvention::ENSEMBL)));
+    }
+
+    public function testFailedInit(): void
+    {
+        $chromosomeAsString = 'FOO11';
+        self::expectException(\InvalidArgumentException::class);
+        self::expectExceptionMessage("Invalid chromosome: {$chromosomeAsString}. Expected format: chr1-chr22, chrX, chrY, chrM, or without chr prefix.");
+        new Chromosome($chromosomeAsString);
+    }
+}
diff --git a/tests/GenomicPositionTest.php b/tests/GenomicPositionTest.php
new file mode 100644
index 0000000..2a9e06a
--- /dev/null
+++ b/tests/GenomicPositionTest.php
@@ -0,0 +1,33 @@
+<?php declare(strict_types=1);
+
+use MLL\Utils\GenomicPosition;
+use PHPUnit\Framework\TestCase;
+
+final class GenomicPositionTest extends TestCase
+{
+    public function testParseOnSuccessHG19(): void
+    {
+        $genomicPosition = GenomicPosition::parse('chr11:1');
+        self::assertSame('chr11:1', $genomicPosition->toString());
+    }
+
+    public function testParseOnSuccessGRC37(): void
+    {
+        $genomicPosition = GenomicPosition::parse('11:1');
+        self::assertSame('11:1', $genomicPosition->toString());
+    }
+
+    public function testParseOnSuccessHGVSg(): void
+    {
+        $genomicPosition = GenomicPosition::parse('chr11:g.1');
+        self::assertSame('chr11:1', $genomicPosition->toString());
+    }
+
+    public function testParseOnError(): void
+    {
+        $genomicPositionAsString = '11:1test';
+        self::expectException(\InvalidArgumentException::class);
+        self::expectExceptionMessage("Invalid genomic position format: {$genomicPositionAsString}. Expected format: chr1:123456.");
+        GenomicPosition::parse($genomicPositionAsString);
+    }
+}
diff --git a/tests/GenomicRegionTest.php b/tests/GenomicRegionTest.php
new file mode 100644
index 0000000..f98b9da
--- /dev/null
+++ b/tests/GenomicRegionTest.php
@@ -0,0 +1,84 @@
+<?php declare(strict_types=1);
+
+use MLL\Utils\GenomicPosition;
+use MLL\Utils\GenomicRegion;
+use PHPUnit\Framework\TestCase;
+
+final class GenomicRegionTest extends TestCase
+{
+    public function testParseOnSuccessUCSC(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:1-2');
+        self::assertSame('chr11:1-2', $genomicRegion->toString());
+    }
+
+    public function testParseOnSuccessEnsembl(): void
+    {
+        $genomicRegion = GenomicRegion::parse('11:1-2');
+        self::assertSame('11:1-2', $genomicRegion->toString());
+    }
+
+    public function testParseOnSuccessHGVSg(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.1-2');
+        self::assertSame('chr11:1-2', $genomicRegion->toString());
+    }
+
+    public function testParseOnError(): void
+    {
+        $genomicRegionAsString = '11:1_2';
+        self::expectException(\InvalidArgumentException::class);
+        self::expectExceptionMessage("Invalid genomic region format: {$genomicRegionAsString}. Expected format: chr1:123-456.");
+        GenomicRegion::parse($genomicRegionAsString);
+    }
+
+    public function testStartIsGerateThenEnd(): void
+    {
+        $genomicRegionAsString = '11:2-1';
+        self::expectException(\InvalidArgumentException::class);
+        self::expectExceptionMessage('End (1) must be greater than start (2)');
+        GenomicRegion::parse($genomicRegionAsString);
+    }
+
+    public function testContainsGenomicPositionIsTrue(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.1-20');
+        self::assertTrue($genomicRegion->containsGenomicPosition(GenomicPosition::parse('chr11:20')));
+    }
+
+    public function testContainsGenomicPositionIsFalse(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.1-20');
+        self::assertFalse($genomicRegion->containsGenomicPosition(GenomicPosition::parse('chr11:21')));
+    }
+
+    public function testContainsGenomicRegionIsTrue(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.1-20');
+        self::assertTrue($genomicRegion->containsGenomicRegion(GenomicRegion::parse('chr11:19-20')));
+    }
+
+    public function testContainsGenomicRegionIsFalse(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.1-20');
+        self::assertFalse($genomicRegion->containsGenomicRegion(GenomicRegion::parse('chr11:21-22')));
+    }
+
+    public function testCoversGenomicRegionIsTrue(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.20-30');
+        self::assertTrue($genomicRegion->isCoveredByGenomicRegion(GenomicRegion::parse('chr11:g.15-35')));
+    }
+
+    public function testIntersectsFullyWithGenomicRegionIsTrue(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.20-30');
+        self::assertTrue($genomicRegion->intersectsWithGenomicRegion(GenomicRegion::parse('chr11:g.15-35')));
+    }
+
+    public function testIntersectsWithGenomicRegionIsFalse(): void
+    {
+        $genomicRegion = GenomicRegion::parse('chr11:g.20-30');
+        self::assertFalse($genomicRegion->intersectsWithGenomicRegion(GenomicRegion::parse('chr11:15-19')));
+    }
+}